Valve job

Next on the agenda was a rough idle issue. After replacing the fuel injectors, I was concerned that things still weren't exactly 100%. We adjusted the lambda at the same time. My amateur analysis was an air leak or idle control unit. The plugs were oiling up as well.

To get a better handle on what was happening, we did a compression test. The results were not encouraging. Large discrepancies across the cylinders with #1 down a fair way. "Valve job" was probably not what I wanted to hear, but that's what was needed. Before I could change my mind, Pete had it in bits and had sent out the heads.

The top end was a bit of a mess. The valley manifold gasket was shot and leaking water. The heads were gunked up with 20 years worth of exhaust crud. The guides were toast. All the rubber bits were rock hard and were likely sources of air leaks. Not good.

After disassembly, the heads were sent off to be cleaned up and crack tested, the cams were examined for any problems and the manifold was also sent for a good cleaning. As part of the "while we're at it" theory, the exhaust manifold and rocker covers were HPC-coated to bring them back to new.

Repair items included three welds to the heads, polishing the cams and bearings, hot tanking the heads, intake manifold and plenum, cleaning the piston tops, new hoses and a check of the fuel head.

Then of course, there was the matter of the collapsed motor mounts, the timing belt and sprocket that needed to be renewed, gaskets, clamps, fluids ... did I ever listen to those people who said don't play around with old Merc's, it will only cost money? Nope.

At this stage, it's almost reassembled and we are waiting for some smaller parts to finish up. This should be interesting. With an upper end rebuild and all the air leaks gone, I might finally get to see how a real 560 engine performs.

It's been good to see that my mechanic is really getting into this project. So much so that he's actually been sniffing the boxes that the parts came in. Is that weird?